1. Field of the Invention
This invention pertains to hoisting devices and particularly to winch or line drum hoisting devices in which an abnormally long line must be moved vertically through a large range of speeds.
2. Description of the Prior Art
Long line winch or drum drives have generally been costly to manufacture and frequently have required several stages of external transmissions to achieve adequate load capacity and a high range of speed ratios. In other instances, a variable-speed input motor was required to get variable speed ranges. In addition to these prior art devices being expensive, they frequently were impractical in use in remote areas, such as at oilfields and the like.